Machines for the sorting of bulk products being supplied in a continuous parallel stream are well known. Such sorting machines comprise a feeding unit, an analysis unit, a removing unit and a discharge unit. The feeding unit supplies the stream of products to be sorted in a continuous manner to the analysis unit. The analysis unit analyses each product in the product stream individually for one of several previously selected properties such as colour, shape and texture. This analysis is preferably performed by optical observation. Based on this analysis, the analysis unit will investigate whether the individually inspected product satisfies well-defined criteria with respect to the observed properties. If the product does not satisfy these criteria, the removal unit, controlled for this purpose by the analysis unit, will remove the product from the product stream. The products that meet the criteria are collected by the discharge unit for further processing.
An example of such a sorting machine can be found in the international patent application WO 2004/82855 A1, in particular FIG. 2. This international patent application relates to a free-flight sorting machine in which the feeder unit is a conveyer belt. The products leave the conveyer belt with a speed vector determined by this conveyer belt. The analysis of the products and, if necessary, their subsequent removal, takes place when these products propagate in a rather horizontal direction as shown in FIG. 2. The products that meet the criteria and therefore remain in the product stream are collected by a discharge unit containing a curved guide plate which guides the sorted products to a subsequent conveyer belt.
Another example of such a sorting machine can be found in the international patent application WO 2001/07950 A1, in particular FIG. 1. This international patent application also relates to a free flight sorting machine whose feeding unit is a conveyer belt. Here also, the products leave this conveyer belt with a velocity vector determined by this conveyer belt. The analysis of the products and, if required, the subsequent removal take place when these products propagate in a rather vertical direction as shown in this FIG. 1. The products that meet the criteria and therefore remain in the product stream are collected by a discharge unit, which guides the sorted products via a curved guide plate to a subsequent conveyer belt.
Another type of sorting machine is described in the European patent application EP 1 726 372 A1, in particular, in FIG. 1. The feeding unit includes a conveyer or vibrating table followed by a chute. The products leave the conveyer belt with a small forward velocity but when sliding over this chute, they will accelerate under the influence of gravity. The products leave the chute with a velocity vector determined by the curvature and the positioning of said chute. The analysis of the products and, if required, their subsequent removal, takes place when these products are moving in a rather vertical direction. Sorting machines of this type are known as free-fall sorting machines.
A requirement for such sorting machines is that they do not or only to a minor extent affect the properties and the orientation of the products when the products are moving through the sorting machine. This requirement is even more important once the products have been analysed and sorted.
The present application teaches a guide plate that does not affect or only to a limited degree affects the properties and orientation of the sorted products. The present application teaches for this purpose a guide plate that maintains the orientation of the products. In addition, it teaches a sorting machine that comprises such a guide plate.